Unfortunately this is what happens with some younger people who has that 4chan mentality of helping /b/ros out.
And they did sell early to others. Which in turn someone/people gave an ISO of it to a group member who in turn released it p2p.
Stupid. It won't take them long to find out who did it, as from what I believe each disc has a signature number/serial in the data on printing, so each copy is individually numbered. And its easy to trace to a store where it was sold to.
Now if its a huge brand name store, Rockstar in the future may choose never to supply them again, all because of one person who thought they were being cool.
It could also force publishers to deliver on the date of release instead of a few days earlier, to minimize leakage etc.
Hey hum, dumb people will continue being dumb.
Yeah it gets rather damn annoying.